What is the submission timestamp?
The submission timestamp is the date and time when you submitted your return. If you are living in a different time zone than the one shown, you will need to adjust the time shown to your local time in order to see if your return was filed on time. For example, if you're in the Pacific time zone but the timestamp is in Mountain time, you'll need to subtract an hour.
The timestamp is used when processing your return, unless you are filing after the due date or are resubmitting a rejected return that was filed on-time. If you are resubmitting a timely filed federal return, the IRS allows a grace period to correct the rejected return. During that period the original timestamp of the rejected federal return will be used. Otherwise, if you are filing after the due date for the return, the date the return is received by the IRS will be used to determine when the return was filed, not the timestamp.